Method of removing hair from hides.



" UNITED stm' rns PATENT oFFIoE.

LEWIS cn'nnssmm, os'scnanron, rnnnsnvmm.

mnrnon or REMOVING HAIR mom moss.

The object of my invention is the provision of an improved method ofremoving hair from hides preparatory to tanning the same,

which method shall effect a saving in time and reduce the cost ascompared with common methods now in use for a similar purpose.

I have ascertained that the animal fat acids at the base of the hair ina hide will be saponified by the action of hydrated oxid of bariumforming salts miscible in water. The reaction effectively loosens thehair so that it will fall out or be easily removable.

To commercially and .thus ractically employ the hydrated oxid of ariu'mfor removing the hair from hides I have devised two specific methods. Incarrying out the first specific method a bath is formed by adding bariumsulfid to Water. In'the bath the barium sulfid is at once decomposed,forming a solution of hydrated oxid of barium and barium sulf-hydrate.To convert the barium sulf-hydrate into the hydrated oxid of barium, andso make available all the barium without any waste, sufficient lime,referably in the form. of milk of lime, is ad ed to the bath, thusconverting the sulf-hydrate into the hydrated oxid of barium.

The reaction upon the addition of the lime is as follows:

a( 2+ 2 2+ (Gas)? "the sulf-hydrate of barium into hydratedSpecification of Letters lfatent. Application flled September '16, 1907.Serial No. 393,210.

Patented Jan. 4, 1910.

oxid of barium. The amount will, of course, depend upon the size of thebath. To determine when sufficient lime has been added, fr0m t1me totime a small quantity of the solution may be removed from the bath andtreated in a small vessel with lime, and when this reagent fails tothrow down a preci itate of sulfid of calcium suflicient l1me as beenadded to effect the conversion of the sulf-hydrate of barium into the hdrated oxid. The quantity of lime to e added may also be determlnedexperimentally byl observing the effect of the solution upon t e hidestherein. When the hair fails to loosen obviously the hydrated oxid ofbarium has become exhauted or exists only in a small amount, and limeshould be added until sufficient barium sulf-hydrate is converted intothe hydrated oxid to loosen the hair. When the further attention of limeis not accompanied with the loosening of the hair the barium in the bathhas become exhausted and a new bath is necessary.

The sulfid of barium may be produced by grinding the sulfate of bariumto a fine owder, mixing it with fine coal, and roast- 1n the mixture ina furnace, reducing the su fate to sulfid.

The hides, whether green or salted or cured, are preferably soaked inwater to soften them and toremove all dirt and chemicals, and then theyare immersed in the bath and allowed to remain until the hydrated oxidof barium has acted upon the fat acids at the follicles or base of thehair and decomposed the same. The hides are then withdrawn from the bathand the moved in any convenient way. In some cases the hides preparedfor the bath may be immersed in the primary solution containin thehydrated oxid of barium and the su f-hydrate of barium, and when thehydrated oxid has become exhausted the lime or milk of lime be added toconvert the sulf-hydrate into the hydrated oxid of barium.

In carrying out the second specific method a thorough mixture is formedof lime preferably as hydrated oxid of water slaked lime, barium sulfid,some inert finely ground material, such as sandstone, and a quantity ofwater sufiicient to make a paste or comosition of creamy consistency.Seventy our parts of hydrated oxid of lime, one hundred and sixty nineparts of barium depilation is effected.

sulfid, and a suflicient quantity of the powdered material and water towill in practice constitute a desirable composition for the'purposeintended.

The chemical reactions in the mixture are as follows:

The hides having been cleaned and all chemicals removed, as in the firstspecific method, the paste is applied with a brush or otherwise to thefleshy side of the hides where it is allowed to remain until the Theaction of the hydrated oxid of barium upon the fatty acids present atthe roots of the hair is the same as hereinbefore specified.

From the foregoing description of the two specific methods of procedureit becomes clear that all the barium in the sulfid of barium is madeavailable as hydrated oxid,

and consequently great economy is attained which makes the methodcommercially successful. a

Itis well known that barium sulf-hydrate can be converted into bariumhydrate by. the

action of calcium hydrate, but it remained for me to discover that abath or paste for removing hair from hides and skins could be producedwhich would not disintegrate or destroy to an injurious degree the hairor hides present, thus obviating the difficulties met with in the priorart, by exposing the hides and skins to the action of a depilating bathor paste free to an injurious extent from actlve sulfur containingcompounds of alkali or alkali earth metals, and that substantially allsulfur fromcompositions initially containing such sulfur containingcompounds, as barium sulf-hydrate soluble or in solution could berendered inert in the bath or paste by subjecting them to the action ofcalcium hydrate or substances forming the same, such as lime and water,substantially all of the sulfur into calcium sulfid, with calcium sulfidis practically insoluble in solutions of alkaline nature containingtraces of calcium hydrate or more.- Superior results are obtained inemploying the desulfurized depilators as before described and asrevealed and claimed in the form a paste' in sufiicient quantity toconvert 5 present application, in that barium hydrate .free from sulfurcontaining compounds in an active state readily combines with andsaponifies the fatty acid esters or salts surrounding the follicle ofthe hair, andconverts the same into a miscible condition admitting ofthe ready removal or dislodge ment of said hair, and without destroyingthe hair or the skin or hide to which the compositionis applied fordepilating purposes. By. this procedure the saponifying action of thebarium disclosed by the pr or art, and which facts distinguish anddifferentiate my invention therefromparticular attention being called tothe fact that my depilating solution or pastecontains no sulfur in anactive state, the compositions of which retard the action and destroythe hair and .skinin the prior art, the whole of the sulfur'beingrendered inert in the bath or paste in my method. What I claim is:

1..The method of removing hair from hides consisting in treating thesame with a composition barium hydrate, the quantity of sufficient onlyto the sulf-hydrate oxid of barium.-

2. The method of removing hair from hides consisting in forming acomposition containing sulfid of barium, adding thereto calcium oxid andwater in proportions suflicient only to precipitate substantially allthe sulfur therefrom, and thereafter subj ecting the hides to the actionof the residual compound.

3. The method of removing hair from hides consisting in forming acomposition containing sulfid of barium and inert material, addingthereto calcium oxid and water in proportions sufficient only toprecipitate substantially alljthe sulfur therefrom, and thereaftersubjecting the hides to the action of the residual com ound.

In testimony whereof I a 2: my signature inpresence of two witnesses.

LEWIS CHEESEMAN.

calcium oxid and water;

Vitnesses:

CHAS. H. WELLES, Jr., CHAS. D. SANDERSON.

hydrate is not retarded nor the hair destroyed, as in compositions ofbarium sulfhydrate,

calcium hydroxid being

